Abstract
“Achievement of optimal gestational weight gains among all women will require major changes in the care of women throughout their reproductive years.”
There is substantial evidence to suggest that the amount of weight gained during pregnancy has important implications for short- and long-term health outcomes in the mother and her offspring. High gestational weight gains are associated with adverse birth outcomes, including cesarean delivery, macrosomia and large-for-gestational age birth weights. They are also associated with postpartum weight retention [1] and the development of obesity in the years following pregnancy for the mother [1] and child [2]. The association with childhood weight status is of particular concern due to the tracking of obesity from infancy through adolescence and adulthood. Similarly, low gestational weight gains are associated with preterm birth, small-for-gestational age, and failure to initiate breastfeeding. Low weight gains may also lead to the development of obesity, cardiovascular disease and diabetes in the child [3]. Considering the vast public health importance of these health consequences in the mother and the child, the amount of weight gained during pregnancy represents a critical health behavior that should be monitored and can be modified.
In May 2009, the Institute of Medicine (IOM) introduced revised gestational weight gain guidelines based on the most current research findings [4]. The revised guidelines use the WHO's International Obesity Task Force cut points for BMI to specify the amount of weight to be gained by women within BMI categories (BMI <18.5 underweight, 18.5–24.9 normal weight, 25–29.9 overweight and ≥30 obese) [5] and they now include an upper weight gain limit for obese women [4]. At the time of the report, there were insufficient data to provide recommendations specific for women in an obesity class higher than class I (BMI 30–35). The committee acknowledged that women of higher BMI status may be able to gain less weight than recommended if monitored by a physician but could not make a blanket recommendation for all obese women to gain less or no weight during pregnancy. While some physicians have argued for stricter weight gain limits, the committee emphasized that given current gestational weight gain trends, radical changes in healthcare delivery and the social environment are necessary for pregnant women to achieve the new weight gain recommendations. Once these recommendations are met by the majority of pregnant women, they should be reviewed in a timely fashion to evaluate if optimal maternal and child outcomes can be achieved with lower gains. This leads to the current question of “How can we assist women in managing gestational weight gain?”
The lifestyle and behavioral interventions conducted to date provide inconclusive information regarding which strategies may be most effective and efficient for promoting adequate weight gains (within the IOM recommended weight gain ranges) in women across prepregnancy BMI categories. In a recent meta-analysis of 44 randomized controlled trials composed of 7278 women, there was an overall 1.42 kg (95% CI: 0.95–1.89 kg) reduction in gestational weight gain for women who received an intervention (diet, physical activity or mixed intervention) compared with controls. Diet interventions resulted in the greatest reductions in gestational weight gain of 3.84 kg (95% CI: 2.45–5.22 kg) compared with 0.72 kg (95% CI: 0.25–1.20 kg) and 1.06 kg (95% CI: 0.46–1.67 kg) reductions for physical activity and mixed interventions, respectively [6]. However, a Cochrane review of randomized controlled trials concluded that there is insufficient evidence to recommend any intervention for preventing excessive gestational weight gains due to heterogeneity of interventions, small effect sizes and inconsistency of results [7]. As with weight loss interventions in nonpregnant populations, it is likely that the success of a given behavioral intervention is dependent on the specific study population and the type, duration, and intensity of care provided by the intervention. For example, among obese women, more intensive dietary counseling, individualized goal setting and theoretically designed interventions may be needed to prevent excessive weight gain compared with normal weight women as was demonstrated by Wolff and colleagues [8]. In both pregnant and nonpregnant populations, diet and/or physical activity interventions are integral for weight management but the incorporation of psychological, emotional and social support are likely necessary to promote behavior change.
“… healthcare providers of pregnant women continue to have a unique and influential role in assisting women with gaining appropriate amounts of weight during pregnancy.”
Despite the current lack of research-based recommendations regarding the management of gestational weight gain, healthcare providers of pregnant women continue to have a unique and influential role in assisting women with gaining appropriate amounts of weight during pregnancy. However, even after the publication of the revised IOM guidelines, low percentages of women report being counseled correctly about weight gain during pregnancy, if at all [9]. Ideally, healthcare providers should provide guidance that begins prior to conception and lasts throughout the postpartum period and addresses such issues as prepregnancy BMI status, nutritional and physical activity behaviors, stress, mental health, and social support. The inclusion of documentation of prepregnancy BMI, target weight gain, periodic assessment of weight gain and referrals as part of an electronic medical record system would be important steps to standardize the care of pregnant women.
Comprehensive guides for healthcare providers are available [10,11]. The following is a brief description of key areas that need to be addressed when assisting women in managing gestational weight gain:
Women need to be educated about the importance of achieving a healthy BMI status before pregnancy and the risks of having a low (<18.5) or high BMI (>30). These women need to be targeted and informed of the pregnancy and birth complications that are associated with their BMI status, independent of gestational weight gain. This type of information can be provided by all healthcare providers who are in contact with women of reproductive ages and be incorporated into public health awareness efforts. Women who express issues of disordered eating or body dissatisfaction should be referred to a mental health provider;
As part of routine prenatal care, women should be educated about the IOM gestational weight gain guidelines and their weight gain should be openly monitored. Gestational weight gain charts based on the guidelines should be used as an illustrative example of the expected pattern of weight gain during pregnancy. They can also assist women in looking beyond the gain from one visit to the next and toward the overall pattern of weight gain [10];
Women need to continually be encouraged to stay physically active throughout pregnancy. Women who were physically active prior to pregnancy should continue with their exercise routines and given modifications, if necessary. Women who were not physically active prior to pregnancy should be provided with examples of activities they can do safely, such as walking, prenatal yoga and other low impact activities;
Women should be reminded that pregnancy requires only modest increases in calories (350–450 calories on average), but great increases in vitamins and minerals, starting in the second trimester. Thus, the myth that they are eating for two must be dispelled. Considering that most women are likely to reduce the amount of time spent undertaking physical activities, especially as the pregnancy progresses, dietary intake is essential for managing gestational weight gain. Unhealthy eating behaviors, such as frequency of consumption of sugar-sweetened beverages, fried foods and highly processed foods, as well as the number of meals eaten at fast food restaurants, should be evaluated and goals to improve these behaviors can be established. Women should be provided with specific examples of nutrient-dense snacks within the appropriate calorie range that they can add to their daily diets. Appropriate referrals for additional counseling by a nutrition specialist should be considered for women not able to follow the targeted weight gains;
Women should be screened for depression. It is estimated that one in seven women develop depression during pregnancy or after giving birth [12]. Depression during pregnancy is associated with both low [13] and high [14] gestational weight gains. Intervention and treatment for symptoms of depression and other psychological factors, such as stress and social support, may be required during pregnancy to assist women in achieving optimal gestational weight gains;
Women should be encouraged to sleep 7–8 h per night [15]. While sleeping may be difficult due to physiological and body size changes, especially towards the end of pregnancy, research is emerging showing the importance of obtaining an adequate number of hours of sleep to sustain a healthy weight [16].
Achievement of optimal gestational weight gains among all women will require major changes in the care of women throughout their reproductive years. Such changes include a range of lifestyle, behavioral and social support approaches at the individual and community levels. Within the last year, research efforts have been initiated by the NIH to elucidate the specific strategies necessary to help women manage gestational weight gains. Though results from this research will be valuable, the healthcare provider remains a crucial part of women's individualized care before, during, and after pregnancy.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.